diff --git a/ChangeLog b/ChangeLog
index 8cc958353..e6ac616c0 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,13 @@
+2007-02-04  Matt Rice  <ratmice@gmail.com>
+
+	* Source/NSTableView.m (-mouseDown:): Return early after tracking a 
+	cell which prefersTrackingUntilMouseUp.
+	* Source/NSPopUpButtonCell.m (+prefersTrackingUntilMouseUp:): Return
+	yes.
+	(-trackMouse:inRect:ofView:untilMouseUp:): Return yes or no
+	depending on whether the mouse went up inside the menu or not.
+	Fixes bug #18946
+
 2007-01-31  Richard Frith-Macdoanld <rfm@gnu.org>
 
 	* Source/GSFontInfo.m:
diff --git a/Source/NSPopUpButtonCell.m b/Source/NSPopUpButtonCell.m
index d5af3d89d..b273a6db7 100644
--- a/Source/NSPopUpButtonCell.m
+++ b/Source/NSPopUpButtonCell.m
@@ -51,6 +51,11 @@ static NSImage *_pbc_image[2];
     }
 }
 
++ (BOOL) prefersTrackingUntilMouseUp
+{
+  return YES;
+}
+
 // Initialization
 /**
  * Initialize a blank cell.
@@ -838,9 +843,10 @@ static NSImage *_pbc_image[2];
   if ([[_menu window] isVisible])
     {
       [self dismissPopUp];
+      return NO;
     }
 
-  return NO;
+  return YES;
 }
 
 /**
diff --git a/Source/NSTableView.m b/Source/NSTableView.m
index e814e8e4d..81233031e 100644
--- a/Source/NSTableView.m
+++ b/Source/NSTableView.m
@@ -3703,14 +3703,27 @@ static inline float computePeriod(NSPoint mouseLocationWin,
 		       * Can never get here from a dragging source
 		       * so they need to track in mouse up.
 		       */
-
-		      // FIXME we probably want to return from here
-		      // if the cell wants to track until mouse up,
-		      // which could cause selections if the mouse leaves the
-		      // cell frame?
+		      NSTableColumn *tb;
+		      NSCell *cell;
+		      
+		      tb = [_tableColumns objectAtIndex: _clickedColumn];
+		      cell = [tb dataCellForRow: _clickedRow];
+		      
 		      [self _trackCellAtColumn: _clickedColumn
 				row: _clickedRow
 				withEvent: theEvent];
+
+		      if ([[cell class] prefersTrackingUntilMouseUp])
+		        {
+		          /* the mouse could have gone up outside of the cell
+		           * avoid selecting the row under mouse cursor */ 
+
+			  /* FIXME this should really send the action
+			   * unfortunately the row isn't currently being
+			   * selected so that would send the action on the 
+			   * wrong row. */
+			  return;
+			}
 		    }
 		  /*
 		   * Since we may have tracked a cell which may have caused